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[on:]

Hi,

I have a maplin USB power adaptor (Code: N69CX).  Is it OK to power my Arduino with this?

On the packet if says the Voltage is 5V and the Current is 1.0A.

Thanks

[Reply #1 on:]

Yes.

[Reply #2 on:]

USB power is required to be regulated 5V and usually can be relied upon to provide at least 0.5A, so such USB power adapters are fine power sources for 5V digital circuitry.

[Reply #3 on:]

If you have a recent Uno, be sure to connect to the USB connector.
Connecting to the barrel jack and/or Vin, 5V is not enough to power the regulator.
Connecting to 5V may damage the Uno's 5V regulator unless you add a diode from 5V to Vin (i.e. across the regulator) - see the LM1117 datasheet for a better description.
http://www.ti.com/lit/ds/symlink/lm1117-n.pdf
Page 12-13, para. 4.0

[Reply #4 on:]

Thanks everyone.

Just to confirm - I am using it to connect to the Arduino's USB port.

I just wanted to make sure that 1 amp wasn't going to do any damage.  I've only been able to find out that a PC USB port outputs up to 0.5 amps to the Arduino, so wanted to check that doubling it wouldn't be too much for it.

[Reply #5 on:]

1 amp is what it can provide, not what it willprovide.

The voltage is the fixed value, not the current.

[Reply #6 on:]

Connecting to 5V may damage the Uno's 5V regulator unless you add a diode from 5V to Vin (i.e. across the regulator) - see the LM1117 datasheet for a better description.
http://www.ti.com/lit/ds/symlink/lm1117-n.pdf
Page 12-13, para. 4.0

YIKES!
I just checked my most recently-purchased UNO and you're right -- there's no protection diode!

(Bad designer! No biscuit!)

Time to heat up the ol' iron.

Thanks for the tip.

[Reply #7 on:]

Yes, I think its a shame they changed the regulator and didn't make it safe to power from the 5V header.